Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: cw filters  (Read 525 times)
ZL2OM
Member

Posts: 3




Ignore
« on: August 28, 2007, 04:09:10 AM »

are dsp cw filters any better than good analogue ones?
Logged
AA4PB
Member

Posts: 12841




Ignore
« Reply #1 on: August 28, 2007, 07:59:43 AM »

The first issue is that filters are more effective in the IF stage than in the audio stage, regardless of the type.

DSP filters can have sharper edges without ringing than analog filters so in general they are more effective. Also a DSP filter generally gives you a lot more options in setting the bandwidth since its all in software.
Logged
N5XM
Member

Posts: 242




Ignore
« Reply #2 on: August 29, 2007, 10:27:20 AM »

If you're just starting out on HF, be patient with yourself.  By the time you've owned two or three rigs you will have a better understanding of how filtering works.  Other than roofing filters, I do not have any IF crystal filters in my Orion, and it works great.  DSP radios allow you to reduce your bandwidth to such a degree, when used in conjunction with pass band tuning and notching, that crystal filters become almost redundant.  Notice that I said "almost" redundant.  On my Orion, the DSP function is called "noise reduction" and it works great as long as I'm copying a signal of decent strength.  There is a loss of gain when you kick in the noise reduction, and after a while you learn how loud the signal needs to be in order to use the NR.  Not all DSP radios are created equal.  

On the other hand, crystal filters in the IF chain are wonderful.  There can be ringing if you try to get too narrow with your choice of filter, as you already know.  Before I got my Orion I had an Omni 6 Plus with every filter slot filled, and that radio was a dandy, pure and simple.  A lot depends on your ear.  It is true that the best filtering device available lies between our ears!  To me, good passband tuning is critical to making filtering work as it should.  Read as much as you can and pick more experienced Hams brains, and you can learn a lot really fast.  I'm very glad to hear you enjoy CW, and hope to work you sometime in the future.  73!
Logged
AB9LZ
Member

Posts: 198




Ignore
« Reply #3 on: September 08, 2007, 02:31:17 PM »

Huh. my IC 746 rings like a bell, while the old school crystal lattice filters in my TS-850 are silky smooth. The Icom has been relegated to phone only use due to the fatigue of listening to the DSP by products, while the TS-850 can be listened to all night, or until the beer runs out ; )

73 m/4
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!